Radio beacons (roadside units, RSUs) and onboard units (OBUs) of this type are used in infrastructure-hound road toll and communication systems. These systems are based on a plurality of geographically distributed stationary radio beacons, which communicate via short-range radio with onboard units of passing vehicles so as to localize them to their limited beacon radio coverage range. This allows location usages by the vehicles to be subjected to tolls, for example, or to supply these with location-specific information. To this end, it is frequently important to be able to associate the radio communication between a radio beacon and an onboard unit located in the vicinity thereof with a particular vehicle, for example so as to identify the communicating vehicle in a camera image of the radio beacon during high traffic density.
At present, radio beacons having a particularly small, strongly directional radio coverage range are generally used for this purpose, for example those according to the dedicated short range communication (DSRC) standard, and are thus specifically associated with each individual lane of multi-lane road. When radio beacons that have a larger radio coverage range, for example according to the wireless access in a vehicle environment (WAVE) standard, are used, additional lane-specific identification devices such as lane antennas, radio direction finding receivers or the like are required to associate the radio communication to vehicles. Both variants require the lane-specific installation of infrastructure on the road, which is accomplished by mounting installations that span the road (“gantries”) or by masts containing mounting booms that are provided on the road. Such mounting installations, masts and booms are not only extremely expensive to set up, but because of the massive design thereof also take up a lot of space and are not attractive, especially in residential areas and natural landscapes.